Apparatus, methods and articles of manufacture for dry pipe sprinkler system

ABSTRACT

Apparatus, methods, and articles of manufacture for maintaining the integrity or pressurization of a dry pipe sprinkler system by preventing damage to auxiliary drains from freezing temperatures are taught. An insulated, heated housing, which may be thermostatically controlled provides a controlled environment about an auxiliary drain, insulated and with a heater. An alarm may be used as well to provide warning if said auxiliary drain retains a predetermined amount of condensate and embodiments may be retrofit about an existing auxiliary drain or be provided with an auxiliary drain for installation upon a dry pipe sprinkler system.

FIELD OF INVENTION

The present inventions relate to dry pipe sprinkler systems orpre-action systems and, more particularly, to auxiliary drains, alsoknown as condensate collectors or drum drips.

BACKGROUND

A dry pipe sprinkler system or pre-action system comprises a firesuppression system that is typically used in structures and areas thatare oftentimes unheated and subject to freezing temperatures. The drypipe sprinkler system includes a network of pipes including branch linesservicing sprinkler heads, risers, and feed mains for delivering waterfrom a water supply to the branch lines. Under normal conditions, thisnetwork of pipes contains a pressurized gas, such as air or nitrogen,which holds closed a dry pipe valve that connects the main supply pipesof main feeds of the sprinkler system to the water supply. When heatfrom a fire opens a sprinkler, the compressed gas is released from thesystem. The resulting drop in pressure causes the dry pipe valve toopen, or trip, thereby releasing water into the main supply lines ormain feeds.

When the network of pipes is filled with the pressurized gas and theambient temperature lowers, condensate can collect in the network ofpipes. If the condensate builds up in the system, then there is a riskthat the condensate will freeze in the pipes. Freezing condensate cancause pipes to leak or burst, or inhibit the flow of water through thebranch lines in the event of fire. For this reason, dry pipe systemsoften include one or more auxiliary drains, also known as condensatecollector arrangements or drum drips which collect condensate from thenetwork of pipes. These auxiliary drains are typically located at lowpoints of the dry pipe system and made of a section of larger diameterpipe serving as a condensate collection area, with a smaller diameterpipe at the top and bottom, serving as supply and drain respectively. Anupper valve functions as a shut-off valve and a lower valve as adrainage valve. An auxiliary drain is drained of condensate by firstclosing the upper valve. This prevents pressurized gas from exiting thesystem when the auxiliary drain is being drained. The drain valve isthen opened and condensate is drained from the condensate collectionarea. Then the drain valve is closed again and the upper valve may bereopened to again allow condensate to be collected.

Whether an auxiliary drain uses a two valve or other arrangement, it mayitself be subject to freezing temperatures, and so be in danger ofdamage from the condensate it collects freezing and/or alternatelyfreezing and thawing. Such damage could lead to failure of the drainand/or the entire system to which the drain is connected. The damage maybe limited through a rigorous drainage schedule and/or insulation on thedrain, but such measures may be less than ideal and/or poorlyimplemented.

SUMMARY

The preferred embodiments provide apparatus, methods, and articles ofmanufacture for maintaining the integrity or pressurization of a drypipe sprinkler system by preventing damage to auxiliary drains fromfreezing temperatures. A housing is used for providing a controlledenvironment about an auxiliary drain, insulated and with a heater. Thehousing is weather resistant and a locking door is provided for accessto the auxiliary drain.

The heater is thermostatically controlled so that it operates when theambient temperature is below 40 degrees Fahrenheit. There are variousentry ways or penetrations into the housing, for the dry pipe, power forthe heater and the like, and these are sealed, minimizing penetrationinto the interior by nuisances such as bees or other unwanted intruders.

An alarm, which may or may not include a trigger component as usedherein, may be provided as well in order to provide warning if saidauxiliary drain retains a predetermined amount of condensate. (forexample, a float switch alone, a float switch connected to an alarm,etc.) Embodiments may, as well, provide a housing that is retrofit aboutan existing auxiliary drain or be provided with an auxiliary drain forinstallation upon a dry pipe sprinkler system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a view of a preferred embodiment.

FIG. 2 shows a side view of the embodiment of FIG. 1.

FIG. 3 shows a front view of the embodiment of FIG. 1.

FIG. 4 shows a side view of the embodiment of FIG. 1.

FIG. 5 shows a view of another preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a preferred embodiment with open door 10. Door 10 is hingedon piano hinge 15 and closes on housing 20. Door 10 and housing 20 aremade of steel and insulated with ½ inch thick foil faced foam boardinsulation provided to retain heat, as will be further described below.It should be noted that in this and other embodiments alternativeconstruction may be used as well, all of which are intended to be withinthe scope of the inventions as defined in the claims herein.

Tabs 21-24 are for mounting upon a concrete pillar, wall or othersurface as may be desired, and turning briefly to FIG. 5 a schematic ofa dry pipe sprinkler system is seen as might be present on a floor of aparking garage or the like with embodiments shown at 1-6 depending fromcorners of the system. Returning to FIG. 1, key lock 25 and attendantlatch 26 is shown on the inside of door 10. Within housing 20, auxiliarydrain 30 is shown, and is mounted to housing 20 with top u-bolt 28 andbottom u-bolt 29. Extending from the top of housing 20 is input pipe 31,which is connected in turn to a dry pipe sprinkler system (not shown.)Upper valve 32 controls input pipe 31 which then leads into condensatecollection area 33. Also at the top of the condensate collection area 33is float type level switch 35 which allows the unit to fill. As isfurther described below however if the unit does fill to a preset level,alarm 52 will be triggered. In this and other embodiments, the floattype level switch 35 may be set so various levels of condensate maytrigger an alarm. Of course, yet other embodiments may dispense with afloat type level switch entirely, and an alarm be set to trigger withany amount of condensate. The alarm, it should be noted, may be pre-set,set upon installation, or set during operation, and be set locallyand/or from a central location in various embodiments.

Depending from condensate collection area 33 is lower drainage valve 34which, when opened, provides for drainage from condensate collector 33through drain 36.

Input pipe 31 travels into housing 20 via pass-through 41, which, as hadbeen described above, is sealed to prevent nuisances such as bees orother unwanted intruders from entering. There may or may not be a seal,a seal may be water resistant or proofed, other protections as known inthe art, etc. may be used as desired in various embodiments. Drain pipe36 travels through pass-through 46, which is also sealed in a similarmanner to pass-through 41. Cap 39 can be removed to drain the auxiliarydrain 30, desirably in an appropriate procedure that maintainspressurization, as is described for example in NFPA 25 guidelines.Although the preferred embodiments are within a locking cabinet, and itmay not be desired to have an Anti-Trip device, e.g., a wire or plate,other embodiments may use an Anti-Trip device e.g., a wire or plate asdesired.

Thermometer 40 displays the temperature inside the housing 20 though itsexternal dial (not shown.) In various embodiments that temperature maybe monitored and an alarm be set to provide warning if the insidetemperature fell below a predetermined level. That alarm may be localand/or be sent to a central location as desired. It should be notedthat, although the preferred embodiments contain an auxiliary drain, itmight be desired in other embodiments to provide a retrofit embodimentto install around an existing auxiliary drain.

Electrical enclosure 50 contains components for an alarm as well asother components such as circuit protection, a relay and terminalblocks. The alarm 52 extends through recess 53 and provides an audiblesound (e.g., buzzer) and light when the auxiliary drain is full ofcondensate. In other embodiments, it should be noted and as wasdescribed above, the alarm may trigger when varying amounts, or any atall, of condensate accumulates. The alarm enclosure 50 is at least aNEMA 4X enclosure in the preferred embodiments as set forth in theNational Electrical Manufacturers Association Standards Publication250-2003.

Conduit 66 provides power to a heater (or heating element, the words areused interchangeably herein) (not shown here, see FIG. 2) and alarm 52,which in the preferred embodiments is 120V and enters the housing 20through pass-through 67, which is sealed similarly to the otherpass-through 41 and 46.

Turning to FIG. 2, a side view of the embodiment of FIG. 1, a heater 65is behind enclosure 50. In the preferred embodiments, the heater issized appropriately, (e.g., a 60 W heater in the preferred embodiments)and provides the interior of housing 20 with an air temperature of from40 to 60 degrees F., which may be set by thermostat, be preset, allowfor setting during or after installation, be set from a central controlarea, etc.

It should be noted that embodiments may provide for centralized controlas well, with the alarm settings, drainage, heater and other componentsbeing monitored and/or manipulated from a central location. Embodimentsmay include as well a test device to confirm the alarm and othercomponents are working correctly, which may as well be local and/oractivated and/or monitored from a central location. The embodiment ofFIG. 1 shows a test pushbutton 54, for example, for testingfunctionality of the alarm system.

Turning briefly to FIGS. 3 and 4, a view of housing 20 with door 10closed is seen. FIG. 3 is a front view with thermometer 40, alarm 52 andkey lock 25 visible. FIG. 4 is a side view of housing 20 with the doorclosed.

The foregoing description is provided as an enabling teaching of theinventions in its currently known embodiments. Those skilled in therelevant art will recognize that many changes can be made to theembodiments described while still obtaining the beneficial results ofthe present inventions. It will also be apparent that some of thedesired benefits of the present inventions can be obtained by selectingsome of the features of the present inventions without utilizing otherfeatures. Accordingly, those who work in the art will recognize thatmany modifications and adaptations to the present inventions arepossible and may even be desirable in certain circumstances and are apart of the present inventions. Thus, the following description isprovided as illustrative of the principles of the present inventions andnot in limitation thereof, since the scope of the present inventions isdefined by the claims.

I claim:
 1. An apparatus for maintaining the integrity of a dry pipesprinkler system, comprising: an auxiliary drain, further comprising aninput pipe, a condensate collection area, and a drain pipe, wherein afirst valve controls fluid passage from said input pipe into saidcondensate collection area, and a second valve controls fluid passagefrom said condensate collection area into said drain pipe; an insulatedhousing with door for providing a heat controlled environment whereinsaid auxiliary drain is at least partially located within said housing,and said condensation collection area is located within said housing; aheater for providing heat to said housing; and, an alarm for providingwarning when said auxiliary drain retains a predetermined amount ofcondensate.
 2. An apparatus as in claim 1 wherein said insulated housingfurther comprises a weather resistant insulated housing.
 3. An apparatusas in claim 1 wherein said insulated housing further comprises a lockingdoor.
 4. An apparatus as in claim 1 wherein said heating element isthermostatically controlled.
 5. An apparatus as in claim 1 furthercomprising an anti trip device.
 6. An apparatus as in claim 1 furthercomprising an exterior temperature readout for providing interiortemperature.
 7. An apparatus as in claim 1 further comprising an alarmto provide a warning if the interior temperature falls below apredetermined level.
 8. An apparatus as in claim 1 where said alarm iscentrally controlled.
 9. An apparatus as in claim 7 where said alarm iscentrally controlled.
 10. An apparatus as in claim 1 further comprisinga test device for providing assurance of proper operation of said alarm.11. An apparatus for maintaining the integrity of a dry pipe sprinklersystem, comprising: an insulated housing with door for providing a heatcontrolled environment for an auxiliary drain, with an input pipe, acondensate collection area, and a drain pipe, wherein said auxiliarydrain is at least partially located within said housing, and saidcondensation collection area is located within said housing; a heaterfor providing heat to said housing; and, an alarm for providing warningwhen said auxiliary drain retains a predetermined amount of condensate.12. An apparatus as in claim 11 wherein said insulated housing furthercomprises a weather resistant insulated housing.
 13. An apparatus as inclaim 11 wherein said insulated housing further comprises a lockingdoor.
 14. An apparatus as in claim 11 wherein said heating element isthermostatically controlled.
 15. An apparatus as in claim 11 furthercomprising an alarm for warning against excessive water conditions. 16.An apparatus as in claim 11 further comprising an exterior temperaturereadout for providing interior temperature.
 17. An apparatus as in claim11 further comprising an alarm for warning if the interior temperaturefalls below a predetermined level.
 18. An apparatus as in claim 11 wheresaid alarm is centrally controlled.
 19. An apparatus as in claim 17where said alarm is centrally controlled.
 20. An apparatus as in claim11 further comprising a test device for providing assurance of properoperation of said alarm.
 21. A method for maintaining the integrity of adry pipe sprinkler system, comprising: providing an auxiliary drain,further comprising an input pipe, a condensate collection area, and adrain pipe, wherein a first valve controls fluid passage from said inputpipe into said condensate collection area, and a second valve controlsfluid passage from said condensate collection area into said drain pipe;providing an insulated housing with door for providing a heat controlledenvironment wherein said auxiliary drain is at least partially locatedwithin said housing, and said condensation collection area is locatedwithin said housing; providing heat to said housing; and, providingwarning when said auxiliary drain retains a predetermined amount ofcondensate.
 22. A method as in claim 21 wherein said insulated housingfurther comprises a weather resistant insulated housing.
 23. A method asin claim 21 wherein said insulated housing further comprises a lockingdoor.
 24. A method as in claim 21 further comprising thermostaticallycontrolling the provision of heat to said housing.
 25. A method as inclaim 21 further comprising providing warning if the interiortemperature falls below a predetermined level.
 26. A method as in claim21 further comprising centrally controlling said alarm.
 27. A method asin claim 21 further comprising providing assurance of proper operationof said alarm.
 28. A method for maintaining the integrity of a dry pipesprinkler system, comprising: providing an insulated housing with doorfor providing a heat controlled environment for providing an auxiliarydrain, further comprising an input pipe, a condensate collection area,and a drain pipe wherein said auxiliary drain is at least partiallylocated within said housing, and said condensation collection area islocated within said housing; providing heat to said housing; and,providing warning when said auxiliary drain retains a predeterminedamount of condensate.
 29. A method as in claim 28 wherein said insulatedhousing further comprises a weather resistant insulated housing.
 30. Amethod as in claim 28 wherein said insulated housing further comprises alocking door.
 31. A method as in claim 28 further comprisingthermostatically controlling the provision of heat to said housing. 32.A method as in claim 28 further comprising providing warning if theinterior temperature falls below a predetermined level.
 33. A method asin claim 28 further comprising centrally controlling said alarm.
 34. Amethod as in claim 28 further comprising providing assurance of properoperation of said alarm.